GraphvizPreview.py

import sublime, sublime_plugin
from subprocess import call
import os
import platform

try:  # python 3
    from .helpers import surroundingGraphviz, graphvizPDF, ENVIRON
except ValueError:  # python 2
    from helpers import surroundingGraphviz, graphvizPDF, ENVIRON


class GraphvizPreviewCommand(sublime_plugin.TextCommand):
    def run(self, edit):
        sel = self.view.sel()[0]

        if not sel.empty():
            code = self.view.substr(sel).strip()
        else:
            code = surroundingGraphviz(
                self.view.substr(sublime.Region(0, self.view.size())),
                sel.begin()
            )

        if not code:
            sublime.error_message('Graphviz: Please place cursor in graphviz code before running')
            return


        pdf_filename = graphvizPDF(code)

        try:
            if platform.system() == 'Windows':
                os.startfile(pdf_filename)
            elif platform.system() == 'Linux':
                call(['xdg-open', pdf_filename], env=ENVIRON)
            else:
                call(['open', pdf_filename], env=ENVIRON)
        except Exception as e:
            sublime.error_message('Graphviz: Could not open PDF, ' + str(e))
            raise e